Optimal pollination conditions for seed set after a self-pollination,an intraspecific cross and an interspecific cross of marrow-stem kale (Brassica oleracea var. acephala)

Summary The effects of different pollination techniques, with and without emasculation and delayed pollination, were investigated to find the conditions for maximum seed set after self-pollination and intraspecific and interspecific crosses of Brassica oleracea var. acephala. The results indicated that the pollination conditions achieving maximum seed set vary with the type of pollination. After controlled self-pollination, the best seed set occurs in bud 3 to bud 10. For the intraspecific cross, the youngest flower and the oldest bud produced the largest number of developed ovules but bud pollination was productive to bud 8. The yields from these two pollination types were best when the female parent was not emasculated. In the interspecific cross with B. campestris cv. Marco the best results came from the youngest flowers and the oldest buds subjected to the standard practice of pollinating directly after emasculation. Possible reasons for these effects are discussed.     

Inheritance of resistance to turnip mosaic virus in Chinese cabbage

Summary Turnip mosaic virus (TuMV) is the most important virus of commercially grown cole crops in many Asian countries, affecting both yield and quality. TuMV-infected Chinese cabbage becomes unmarketable because of the presence of black spots and necrosis often induced by the virus. Resistance breeding is complicated by the existence of five strains of the virus, one of which was discovered in 1985 for the first time in Taiwan. Resistance to strains C1 to C3 is readily available among the Chinese cabbage germplasm at AVRDC, whereas resistance to strains C4 and C5 is rarely found. To elucidate the inheritance of resistance to TuMV, P₁, P₂, F₁, F₂ and BC₁ generations of crosses between the resistant line 0–2 and three susceptible lines, E-7, E-9 and FL-9, were inoculated with strains C4 and C5. Segregation ratios obtained by visual observation and enzyme-linked immunosorbent assay (ELISA) indicate that two recessive genes confer resistance to both TuMV-C4 and TuMV-C5.     

Variation of seed storage proteins in landraces of common bean (Phaseolus vulgaris L.) from Basilicata,Southern Italy

Summary Twenty landraces of common bean (Phaseolus vulgaris L.) from Sarconi and Rotonda two locations of Basilicata, a Southern Italy region, were screened for variation in seed storage proteins (phaseolin and phytohemagglutinin) by polyacrylamide gel electrophoresis (SDS/PAGE and IEF-SDS/PAGE). No variation of the main seed protein fractions was observed within each landrace. Phaseolin patterns type C and T were exhibited from the landraces; the type C resulted predominant with a frequency of 70%. Only the C type was observed for the landraces of Rotonda, T and C for those from Sarconi. Two variants were observed for the phytohemagglutinin by SDS-PAGE, one was common to eighteen landraces. However, these variants submitted to IEF-SDS/PAGE resulted similar to the type T_G2described by Brown. The importance to safeguard these landraces is stressed by the observation that the more spread commercial cultivars of common bean growing in Southern-Italy had a T phaseolin pattern. A reduction of C type diffusion could produce the loss a typical trait of common bean in Mediterranean regions.     

Incompletely dominant single resistance gene for peanut stripe virus in soybean line AGS 129

Summary Inheritance of resistance to a soybean isolate of peanut stripe virus (PStV-strain PN) was studied in three soybean varieties, AGS 129, Ankur, and PI 230971. Genetic analysis was based on necrotic, mosaic and symptomless reactions in inoculated soybeans. A single incompletely dominant gene in AGS 129 was found to confer the resistance to PStV and was tentatively designated as Pst. The homozygous parent AGS 129, possessing the genotype Pst Pst, was immune while Ankur and PI 230971, with a genotype of pst pst, were susceptible showing mosaic symptoms. The heterozygous genotype Pst pst resulting from the cross of either Ankur or PI 230971 with AGS 129 reacted with necrosis, distinctly different from either of the homozygous genotypes. This genotypic effect was confirmed through the phenotypic segregation in BC, F2, and F3.     

Control of postharvest rots of sweet cherries and table grapes with endophytic isolates of Aureobasidium pullulans

Fifty-one endophytic isolates of Aureobasidium pullulans were obtained from the flesh of sweet cherries and extensively screened to evaluate their biocontrol activity against postharvest rots of sweet cherries and table grapes. Preliminary analysis of all isolates by randomly amplified polymorphic DNA (RAPD) with three different primers showed the presence of a high genetic variability and enabled isolates not showing any genetic difference to be discarded. Thirty-five isolates with different RAPD electrophoresis patterns had a wide range of biocontrol activity against Botrytis cinerea and Monilinia laxa on single-wounded berries of sweet cherries and table grapes with a reduction of decay from 10 to 100%. Two isolates (533 and 547) significantly reduced B. cinerea on table grape berries also when applied 6, 12, and 24 h after the pathogen inoculation. In a 2-year period of investigation (1998–1999), a reduction of total rots ranging from 32 to 80% (sweet cherries) and from 59 to 64% (table grape) was achieved with isolates 533 and 547 applied after harvest. Preharvest applications of isolate 547 significantly reduced postharvest rots of sweet cherries and table grapes by 47 and 38%, respectively. On the whole, isolates 533 and 547 were more effective than A. pullulans L47, a biocontrol agent of postharvest diseases with a known activity. Population studies demonstrated that isolate 547 was able to survive under field conditions, to increase its population during cold storage, and to penetrate the flesh of sweet cherries when applied during flowering.     

Elucidation of meiotic nuclear restitution mechanisms in potato through analysis of microtubular cytoskeleton

DNAs of 693 isolates of bacterial blight pathogen of rice, Xanthomonas oryzae pv. oryzae (Xoo), were characterized using PCR-based primers p^JEL1 and p^JEL2. The pathogen populations were grouped into 97 haplotypes based on DNA-banding patterns. An un-weighted pair-group method using arithmetic averages (UPGMA) indicated a high level of diversity in the pathogen isolates (51 lineages of Xoo at a 70% similarity level). Among these, lineages 5, 7, 27, and 29 are widely distributed and others are localized in the northern region of India. The isolates represent lineage-27, were prevalent in the entire disease-prone area in the region except at Ferozepur. Pathotyping data of the representative isolates of each lineage also indicate 17 different reaction patterns on a set of isogenic lines. Resistance genes xa8 and Xa21 were the most effective followed by xa5, and Xa7 against Xoo isolates prevalent in northern India. Different genes in combinations (xa5+xa13, xa5+Xa21, xa13+Xa21, and xa5+xa13+Xa21) in IR24 genetic background provided better protection against all the pathogen isolates tested in this study than did the component genes. This revised version was published online in July 2006 with corrections to the Cover Date.     

Anti-inflammatory properties of clovamide and Theobroma cacao phenolic extracts in human monocytes: evaluation of respiratory burst, cytokine release, NF-κB activation, and PPARγ modulation

There is a great interest in the potential health benefits of biologically active phenolic compounds in cocoa (Theobroma cacao) and dark chocolate. We investigated the anti-inflammatory potential of clovamide (a N-phenylpropenoyl-L-amino acid amide present in cocoa beans) and two phenolic extracts from unroasted and roasted cocoa beans, by evaluating superoxide anion (O(2)(-)) production, cytokine release, and NF-κB activation in human monocytes stimulated by phorbol 12-myristate 13-acetate (PMA). The effects of rosmarinic acid are shown for comparison. Clovamide and rosmarinic acid inhibited PMA-induced O(2)(-) production and cytokine release (with a bell-shaped curve and maximal inhibition at 10-100 nM), as well as PMA-induced NF-κB activation; the two cocoa extracts were less effective. In all tests, clovamide was the most potent compound and also enhanced peroxisome proliferator-activated receptor-γ (PPARγ) activity, which may exert anti-inflammatory effects. These findings indicate clovamide as a possible bioactive compound with anti-inflammatory activity in human cells.     

Microbial processes and community composition in the rhizosphere of European beech - The influence of plant C exudates

Plant roots strongly influence C and N availability in the rhizosphere via rhizodeposition and uptake of nutrients. This study aimed at investigating the effect of resource availability on microbial processes and community structure in the rhizosphere. We analyzed C and N availability, as well as microbial processes and microbial community composition in rhizosphere soil of European beech and compared it to the bulk soil. Additionally, we performed a girdling experiment in order to disrupt root exudation into the soil. By this novel approach we were able to demonstrate that enhanced resource availability positively affected N mineralization and hydrolytic enzyme activities in the rhizosphere, but negatively affected nitrification rates and oxidative enzyme activities, which are involved in the degradation of soil organic matter. Both rhizosphere effects on N mineralization and oxidative enzyme activities disappeared in the girdling treatment. Microbial community structure in the rhizosphere, assessed by phospholipid fatty acid analysis, differed only slightly from bulk soil but was markedly altered by the girdling treatment, indicating additional effects of the girdling treatment beyond the reduction of root exudation. Differences in oxidative enzyme activities and nitrification rates between rhizosphere soil and bulk soil, however, suggest considerable differences in the (functional) microbial community composition.     

Genotyping of Toxoplasma gondii isolates in meningo-encephalitis affected striped dolphins (Stenella coeruleoalba) from Italy

This study reports the occurrence of Toxoplasma gondii in the brain of three striped dolphins (Stenella ceoruleoalba) found stranded on the Ligurian Sea coast of Italy between 2007 and 2008. These animals showed a severe, subacute to chronic, non-purulent, multifocal meningo-encephalitis, with the cerebral parenchyma of two dolphins harbouring protozoan cysts and zoites immunohistochemically linked to T. gondii. Molecular, phylogenetic and mutation scanning analyses showed the occurrence of Type II and of an atypical Type II T. gondii isolates in one and two dolphins, respectively. In spite of the different molecular patterns characterizing the above T. gondii genotypes, the brain lesions observed in the three animals showed common microscopic features, with no remarkable differences among them. The role of T. gondii in causing the meningo-encephalitis is herein discussed.